Observations and modeling of Earth’s transmission spectrum through lunar eclipses:

A window to transiting exoplanet characterization.

E. Palle, M.R. Zapatero, P. Montañes-Rodriguez, R. Barrena, A. Garcia-Muñoz

Lunar eclipse August 16th 2008

We observed the Earth transmission spectrum during a lunar eclipse

NOT, Visible, 0.4-1 μmWHT, Near-IR, 0.9-2.5 μmLa Palma, Canaries

A penumbral eclipse seen from the Moon

JAXA/NHK

Moon here

Lunar explorer "KAGUYA" (SELENE) on February 10, 2009

Umbra

Penumbra

Brigth Moon

Umbra

Umbra/Bright

Bright

Hα

Earth’s Transmission Spectrum

The pale red dot

Palle et al, Nature, 2009

Evolution of the Earth’s Transmission Spectrum during the eclipse: ZJ

Evolution of the Earth’s Transmission Spectrum during the eclipse: O2 dimer band

Modeling efforts: Constructing a true model

Non-radial symmetry Direct transmissionDiffraction, refractionDiffuse light

Earth – moon distance

∞ = exoplanets

JAXA/NHK

Modeling efforts: The alpha value

0 0.5 0.7

Transmission models: Rayleigh atmosphere

Garcia-Muñoz et al, in preparation

Transmission models: Rayleigh atmosphere Garcia-Muñoz et al, in preparation

Difference

Transmission models: Rayleigh + Clouds (8km) + aerosols (Direct +Diffuse)

Diffuse light insensitive to alpha and dominant at short wavelengths

Garcia-Muñoz et al, in preparation

Oxygen complexes in the Earth’s atmosphere: Oxygen dimers

Oxygen at visible wavelengths

Intensity reversal again explained trough diffuse light contribution

Oxygen complexes in the Earth’s atmosphere: Oxygen dimers

Oxygen at near-IR wavelengths

O2•O2

O2•N2

0.5 1.0 1.5 2.0 2.5

Earth’s Reflectance Spectrum: Earthshine

μm

NOT, Visible, 0.4-1 μmWHT, Near-IR, 0.9-2.5 μm La Palma, Canaries

0.5 1.0 1.5 2.0 2.5

Reflected spectrum Transmission Spectrum

CO2 CH4

CH4

O2 CO2

Blue planet?

O2

O2•O2

O2•N2

O2•O2

Palle et al, 2009μm

M8 star + 1 Earth ... with the E-ELT

~5 h

~ 150 h~ 50 h

~ 25 h

20, 100, 500, 1000 spectra combined - SNR 1000

Palle et al, ApJ, submitted

M8 star + 1 Earth ... with the E-ELT

~5 h

~ 150 h~ 50 h

~ 25 h

20, 100, 500, 1000 spectra combined - SNR 1000

Palle et al, ApJ, submitted

Earth’s transmission spectrum in the mid-IR

More Moon Soon ...VISIR @ VLT3CRIRES @ VLT1COMICS @ SUBARUSPEX @ IRTFPalomar & HST21st December 2010: 0.3 – 24

micron

Thank you